This invention relates to an improved electricity-feeding system for heating tape or heating cable and its applications.
Band-form, electrically heat-generating apparatus, which is essentially composed of two parallel electrodes and resistance elements intervened therebetween over the entire length of the electrodes and connected thereto in parallel has already been known as heating tape or heating cable (such heating tape or cable will hereinafter be collectively referred to as "heating tape"). Concretely the heat-generating apparatus is constructed, for example, as follows: a number of thin wires as resistance wires are connected in parallel and in a dispersed manner to two parallel electrodes over the entire length thereof, or a composition comprising powder of e.g. carbon, graphite, metals, etc. as resistance materials are filled between two electrodes, followed by covering the whole with an electrically insulating material such as plastics. Usually a voltage of several hundred volts has been impressed between the electrodes to cause the above resistance wires, etc. to generate heat. This has been utilized for preventing the freeze of water pipe, the temperature-maintenance of pipe lines, etc.
Referring to the drawings, the prior art and the present invention will be described.